/Engine/Source/Editor/UnrealEd/Classes/Editor/EditorEngine.h
Represents the current selection state of a level (its selected actors and components) from a given point in a time, in a way that can be safely restored later even if the level is reloaded
struct FSelectionStateOfLevel
TArray<FString...
SelectedActors
Path names of all the selected actors
TArray<FString...
SelectedComponents
Path names of all the selected components